AI Research Atlas

Kimi K2

Moonshot AI · 11 July 2025

1T-parameter (32B active) open-weights MoE trained with the MuonClip optimizer on 15.5T tokens, with zero reported loss spikes and a focus on agentic tool use.

First open-weights model past 1T parameters, aimed squarely at agents. It uses MuonClip (Muon plus QK-clip) for stable training, large-scale synthetic agentic tool-use data, and joint RL with real and simulated environments. Non-thinking model.

Date
Friday, 11 July 2025
Lab
Moonshot AI
Kind
open-weights
Access
open weights

Figures

MeasureValueMeasured by
SWE-bench Verified (agentic, single attempt)65.8%
bash/editor tools, no test-time compute
company
Tau2-Bench66.1company
LiveCodeBench v653.7company
GPQA-Diamond75.1company

Modified MIT license, with attribution required above 100M MAU or $20M monthly revenue. 128K context. Paper on arXiv 2025-07-28. Release date from HF repo commits (2025-07-11) and Epoch AI.

Sources

  1. huggingface.co/moonshotai/Kimi-K2-Instruct
  2. arxiv.org/abs/2507.20534
  3. simonwillison.net/tags/ai-in-china/?page=2

This record was checked against its sources on 6 October 2026. How we check